The efficacy of many contemporary pharmaceutical compounds intended to treat neurological and physiological conditions is limited by their inability to cross the blood-brain barrier. As a result, large molecules that may have neurological activity cannot be administered orally or through injection into the bloodstream because the blood-brain barrier serves as a filter to keep these molecules from leaving the bloodstream and entering the brain and spinal cord. Currently there are three alternative approaches to achieving blood-brain barrier access. The first is to introduce pharmaceutical compounds by direct injection into the brain through the skull. While such treatments have demonstrated some success the possibility of infection coupled with the complexity and expense of such procedures have limited their practical usefulness. Additionally, there is resistance among many patients to the administration of such injections directly into the skull. The second approach involves the utilization of chemical agents which temporarily break down the blood-brain barrier in order to allow molecules to enter the central nervous system. At present, this approach is in the very early stages of development and carries with it the potential for allowing molecules of all sizes (including undesirable compounds) to cross the blood-brain barrier. This approach, unless and until it can be refined to allow for greater selectivity in crossing the blood-brain barrier, carries with it serious risks. The third approach, pioneered by the present inventor, involves developing small molecules which can mimic the activities of bioactive molecules yet can pass through the blood-brain barrier following oral administration or administration through injection into the bloodstream.
Therefore, there is a need for the development of small molecules that can mimic physiological activities of bioactive molecules and can cross the blood-brain barrier efficiently without requiring complete degradation of the blood-brain barrier.
It is accordingly an object of the present invention to provide such compounds which can either mimic the actions of molecules normally unable to cross the blood-brain barrier or which can stimulate other, unexpected physiological activities.
It is an additional object of the present invention to produce pharmaceutical medicaments configured from such compounds and to provide methods for using these pharmaceutical compositions to treat a variety of physiological, neurological, and psychological disorders and disease conditions.